One opening had a rounded top, the other pointed, both cut into the earth itself rather than built from stone. Neither was accessible at the time of observation, and photographs could only confirm the possibility, not the certainty, that what lay behind them was a souterrain, an underground passage or chamber, usually stone-lined, that served early medieval communities for storage, refuge, or both.

The fort in which they sit is a promontory fort, a type of enclosure that makes use of a naturally defensive headland, cutting it off from the mainland with an earthwork or bank across the neck of land. The Dunworly example is a coastal one, and the souterrain, if that is indeed what the openings lead to, would have been concealed within its interior. Its existence came to light only through a chance combination of storm damage and local knowledge, reported by Domnall Fleming. What the erosion revealed is now part of the record for County Cork, though the passages themselves remain out of reach.